90% of the changes in TESTFLAGS in oasis test suite are restricting tests run to the last one which was failing.

This task can be done automatically by ounit itself:
* run once
* write tests that failed + their timing in a file ounit.state / _build/ounit.state
* let the user fix the test
* read ounit.state
* run tests with the one failing first and the fastest
* allow to run all tests in level + 1 as well (may code this possibilty in >::)
* if one the previous fail, skip the remaining